THE STEADINESS OF ISOMETRIC CONTRACTIONS IS SIMILAR BETWEEN UPPER AND LOWER EXTREMITY MUSCLE GROUPS

An inverse dynamics musculoskeletal model of the lower extremity was combined with an optimization technique to estimate individual muscular forces and powers during stair ascent and descent. Eighteen Hill-type musculotendon actuators per leg were combined into the eleven functional muscle groups based on anatomical classification to drive the model in the sagittal plane. Simulation results illustrate the major functional differences in plantar flexors of the ankle and extensors of the knee and hip joints during ascent and descent. The results of this study not only could be employed to evaluate the rehabilitation results in the elderly but also could be used to design more anthropometric assistive devices with optimum power consumption.

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Relationships between lower extremity strength and the multi-directional reach test in children aged 7 to 12 years

Hong Kong Physiotherapy Journal ◽

10.1142/s1013702519500136 ◽

2019 ◽

Vol 39 (02) ◽

pp. 143-150

Author(s):

Benjaporn Hirunyaphinun ◽

Soontharee Taweetanalarp ◽

Anong Tantisuwat

Keyword(s):

Lower Extremity ◽

Flexor Muscle ◽

Limits Of Stability ◽

Knee Flexor ◽

Lower Extremity Muscle ◽

Lower Extremity Strength ◽

Flexor Muscles ◽

Muscle Groups ◽

Control Balance ◽

Hip Flexor

Objective: This study investigates the relationships between the Multi-Directional Reach Test (MDRT) and lower extremity strength in typical children. Methods: The MDRT including forward, backward, leftward, and rightward directions was measured in 60 children aged between 7 and 12 years old with typical development. The lower extremity muscle groups were measured using a hand-held dynamometer. Results: The reaching score in each direction had positive relationships with the strengths of several lower extremity muscle groups ([Formula: see text] to [Formula: see text]). Only the strengths of the hip flexor and knee flexor muscles significantly correlated with the MDRT scores in all directions ([Formula: see text] to [Formula: see text]). Conclusion: This study highlights the strength of the hip and knee flexor muscle groups as being important domain to control balance in all directions. These findings may be used for therapists in planning a balance program to improve the limits of stability.

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The Effects of Lower Extremity Muscle Fatigue on Dynamic Balance in Volleyball Players

Iranian Rehabilitation Journal ◽

10.32598/irj.19.1.1003.1 ◽

2021 ◽

Vol 19 (1) ◽

pp. 51-58

Author(s):

Nastaran Ghotbi ◽

Keyword(s):

Lower Extremity ◽

Muscle Fatigue ◽

Repeated Measures ◽

Dynamic Balance ◽

Knee Extensors ◽

Balance Test ◽

Lower Extremity Muscle ◽

Adductor Muscles ◽

Volleyball Players ◽

Muscle Groups

Objectives: Lower extremity muscles are critical for maintaining dynamic balance and athletic performance. Fatigue of these muscles may affect dynamic balance. It is unclear whether fatigue in a particular muscle group can affect dynamic balance more than that in other groups. This study was conducted to evaluate and compare the effects of fatigue in 5 muscle groups on dynamic balance in volleyball players. Methods: Fifteen healthy male volleyball players separately performed the Star Excursion Balance Test before and immediately after the occurrence of fatigue of ankle Plantar Flexor (PF), knee extensor, knee flexor, hip abductor, and hip adductor muscles. Composite reach distance and distance in anterior, posteromedial, and posterolateral directions were recorded, accordingly. Results: Repeated-measures Analysis of Variance (ANOVA) data indicated that fatigue of all muscle groups significantly decreased the mean score of composite (P<0.001). Anterior, posteromedial, and posterolateral distance scores decreased following muscle fatigue of knee extensors and ankle PFs (P<0.05). Discussion: This study suggested that regarding composite reach score, fatigue of ankle, knee, and hip muscles similarly decreased dynamic balance. However, evaluating three main directions revealed that knee extensors and ankle PFs muscles fatigue presented more prominent effects on the explored volleyball players’ balance, compared to the other muscles.

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Joint Torque and Mechanical Power of Lower Extremity and Its Relevance to Hamstring Strain during Sprint Running

Journal of Healthcare Engineering ◽

10.1155/2017/8927415 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 6

Author(s):

Yunjian Zhong ◽

Weijie Fu ◽

Shutao Wei ◽

Qing Li ◽

Yu Liu

Keyword(s):

Lower Extremity ◽

Stance Phase ◽

Swing Phase ◽

Joint Torque ◽

Mechanical Power ◽

Movement Direction ◽

Joint Torques ◽

Sprint Running ◽

Lower Extremity Muscle ◽

Muscle Groups

The aim of this study was to quantify the contributions of lower extremity joint torques and the mechanical power of lower extremity muscle groups to further elucidate the loadings on hamstring and the mechanics of its injury. Eight national-level male sprinters performed maximum-velocity sprint running on a synthetic track. The 3D kinematic data and ground reaction force (GRF) were collected synchronously. Intersegmental dynamics approach was used to analyze the lower extremity joint torques and power changes in the lower extremity joint muscle groups. During sprinting, the GRF during the stance phase and the motion-dependent torques (MDT) during the swing phase had a major effect on the lower extremity movements and muscle groups. Specifically, during the stance phase, torque produced and work performed by the hip and knee muscles were generally used to counteract the GRF. During the swing phase, the role of the muscle torque changed to mainly counteract the effect of MDT to control the movement direction of the lower extremity. Meanwhile, during the initial stance and late swing phases, the passive torques, namely, the ground reaction torques and MDT produced by the GRF and the inertial movement of the segments of the lower extremity, applied greater stress to the hamstring muscles.

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An Electronic Ski Binding Design with Biofeedback

Journal of Mechanical Design ◽

10.1115/1.3254805 ◽

1980 ◽

Vol 102 (4) ◽

pp. 677-682 ◽

Cited By ~ 7

Author(s):

D. K. Lieu ◽

C. D. Mote

Keyword(s):

Lower Extremity ◽

Model Reference ◽

Emg Signal ◽

Lower Extremity Muscle ◽

Leg Axis ◽

State Estimators ◽

Muscle Groups ◽

Model Reference Adaptive ◽

Model Oscillator ◽

Anterior Posterior

A ski release binding releases the ski boot from the ski for loading environments potentially injurious to the lower extremity. The concept of using a model reference adaptive control system to control ski binding release is explored. Model reference oscillators simulate torsion about the longitudinal leg axis and anterior-posterior bending of the lower extremity. The model oscillator coefficients are adjusted depending upon processed EMG signal levels from lower extremity muscle groups, which serve as state estimators. Background on release binding design, binding circuit diagrams and the results of preliminary tests on a binding are presented in this paper.

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